Study on CO₂ Capture and Tar Removal Characteristics of a Newly Developed Ca-based Sorbent

A CaO-based sorbent (Ca-Al-Fe) was newly developed using sol-gel method, of which the performance in tar removal and CO₂ capture was examined. Results show that the Ca-Al-Fe sorbent, with main components of CaO, Ca₁₂Al₁₄O₃₃ and Fe₂O₃, can capture the CO₂ and reduce the evolution of tar species in the pyrolysis of wheat straw. The performance of Ca-Al-Fe sorbent has been significantly improved in cyclic CO₂ capture, compared to ordinary CaO. After 20 cycles of "carbonation-calcination" reaction, the CO₂ capture capacity and CaO conversion rate of Ca-Al-Fe sorbent are slightly reduced, from 0.42 mg/mg and 84% to 0.34 mg/mg and 67%, accordingly, while its mechanical strength is remarkably improved. Compared with those sorbents mentioned in relevant literatures, the newly developed Ca-Al-Fe sorbent has better performance in cyclic carbonation.